This invention relates to communication apparatus, and particularly to apparatus for transferring data between first and second channels where the data format (byte size or frequency) on one channel is incompatible with the data format on the other channel.
In communication apparatus for transmitting data of one byte size to another (such as 8-bit to 16-bit words, and vice versa) or at different speeds (for example, 8 MHz to 4 MHz, and vice versa) it is common to employ a first-in, first-out (FIFO) register so that words of one type are sequentially stored in the register in the size and at the frequency of the sending apparatus, and are read out in sequence at the size and frequency of the receiving apparatus. However, such apparatus has not been altogether effective in handling complex communications, such as communications between a large plurality of terminals and/or processors. The present invention, therefore, is directed to a more sophisticated device having the appearance of a first-in, first-out apparatus, yet is capable of handling the complexity of a large data communication network.